A compression fitting is typically a tubular sleeve made of plastic or metal and containing seals. To produce a joint between two pipe ends, the fitting is slid over the ends of the pipes and then compressed radially to form a leak resistant joint between the pipe ends. The joint has considerable mechanical strength and is self-supporting. A crimping tool is used to compress the fitting on the pipe ends. A typical crimping tool includes at least two arms or end portions. A drive mechanism, such as a hydraulic piston acted upon by hydraulic pressure from a pump within the tool, is used to move the arms. In some embodiments, at least a portion of the arms may be moved radially inward during the crimping operation to directly crimp the fitting. In other embodiments, the arms may actuate a crimp ring that crimps the fitting. Typically, the crimp ring includes two to seven ring segments connected together. The end portions of the crimping tool couple to pivot ports or indentations defined in opposing crimp ring segments. In general, crimp rings are used to crimp a fitting having a diameter greater than approximately 2.5-inches. Some existing crimp slings are used on diameters as small as 42-mm or 1½″, such as the multi-segment crimp slings made by Mapress.
Referring to FIG. 1, a typical, non-articulating actuator arm 2 and crimp ring segment 6 are illustrated in a top view. Actuator arm 2 and crimp ring segment 6 only allow for in-line engagement of the arm with the crimp ring. With in-line engagement, actuator arm 2 is parallel to the plane of crimp ring segment 6 and perpendicular to an axial centerline A of the tube T to be fitted. However, an operator does not always have such access to crimp a fitting. A solution in the art has been to provide an articulating connection between actuator arm 2 and crimp ring segment 6, allowing the operator to access and crimp the fitting at an angle.
Referring to FIGS. 2A-B, a typical method according to the prior art for articulating an actuator arm 2 relative to a crimp ring segment 6 is illustrated. In FIG. 2A, the actuator arm 2 is shown in a top view articulated relative to crimp ring segment 6. In FIG. 2B, a portion of actuator arm 2 engaging a portion of crimp ring segment 6 are shown in cross-section. Actuator arm 2 includes a hemispherical-shaped end 3 and a pivot hole 4. Crimp ring segment 6 defines an indented swivel point 8. To provide the articulating connection, hemispherical-shaped end 3 of arm 2 is disposed in indented swivel point 8. The mating of hemispherical-shaped end 3 with the deep indented swivel point allows arm 2 to articulate relative to ring segment 6, as illustrated by path S in FIG. 2A. This conventional articulating connection enables an operator to actuate crimp ring segment 6 with actuator arm 2 when there is obstructed or limited accessibility.
During a crimp operation, a drive member contacts arm 2 causing it to pivot about a pin (not shown) in pivot hole 4. Hemispherical-shaped end 3 disposed in indented swivel point 8 transfers force and motion of actuator arm 2 to crimp ring segment 6, which is itself typically connected to another segment (not shown) by a pivot pin. Hemispherical-shaped end 3 is able to slide in indented swivel point 8 as arm 2 and crimp ring segment 6 are separately pivoted. Unfortunately, the conventional articulating connection between arm 2 and crimp ring segment 6 provides only a single point of contact or a limited area of contact between the arm 2 and segment 6 during the crimping operation. With such limited contact, the stress on the components, such as arm 2, increases; therefore, it is desirable to have an articulating connection between an arm and a crimp ring segment that provides a greater amount of contact therebetween. Furthermore, the conventional articulating connection may unduly fatigue the arm 2 or crimp ring segment 6 as they are pivoted during the crimping operation. In addition, the conventional articulating connection between the arm 2 and crimp ring segment 6 may require tedious and expensive machining of a cast crimp ring segment 6 to produce a suitable indented swivel point 8 and may similarly require tedious and expensive machining a cast arm 2 to produce a suitable hemispherical-shaped end 3.
Teachings of the present disclosure are directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.